1. 项目创建

创建一个空maven项目:

2. spring

(1) 导包

 <dependency><groupId>org.springframework</groupId><artifactId>spring-context</artifactId><version>5.3.22</version></dependency>

(2) 配置类

@Configuration
public class SpringConfig {}

3. mybatis

(1) maven导包

    <dependency><groupId>org.mybatis</groupId><artifactId>mybatis</artifactId><version>3.5.13</version></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.23</version></dependency>

(2) mybatis配置文件

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configurationPUBLIC "-//mybatis.org//DTD Config 3.0//EN""https://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration><properties resource="jdbc.properties"></properties><environments default="development"><environment id="development"><transactionManager type="JDBC"/><dataSource type="POOLED"><property name="driver" value="${driver}"/><property name="url" value="${url}"/><property name="username" value="${username}"/><property name="password" value="${password}"/></dataSource></environment></environments><mappers><!--指定mapper映射文件在哪--><mapper resource=""/></mappers>
</configuration>

(3) 连接配置文件

driver = com.mysql.cj.jdbc.Driver
url = jdbc:mysql://localhost:3306/stu
username = root
password = xjy1234

(4) mapper映射文件

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapperPUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""https://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.xjy.Mapper"></mapper>

(5) 在spring配置类中注册sqlsession的bean

    @Beanpublic SqlSession getSqlSession() throws IOException {return new SqlSessionFactoryBuilder().build(Resources.getResourceAsStream("MybatisConfig.xml")).openSession();}

springMVC

(1) maven导包

	<!--需要注释掉上面引入的spring-context,不然可能会引起版本冲突(spring-webmvc已经含有spring-context)--><dependency><groupId>org.springframework</groupId><artifactId>spring-webmvc</artifactId><version>6.0.11</version></dependency><dependency><groupId>jakarta.servlet</groupId><artifactId>jakarta.servlet-api</artifactId><version>5.0.0</version></dependency><dependency><groupId>com.fasterxml.jackson.core</groupId><artifactId>jackson-databind</artifactId><version>2.13.3</version></dependency>

(2) springMVC配置类

@Configuration
@EnableWebMvc
public class MvcConfig{
}

(3) 初始化类

public class servletInit extends AbstractAnnotationConfigDispatcherServletInitializer {@Overrideprotected Class<?>[] getRootConfigClasses() {return new Class[]{SpringConfig.class};}@Overrideprotected Class<?>[] getServletConfigClasses() {return new Class[]{MvcConfig.class};}@Overrideprotected String[] getServletMappings() {return new String[]{"/"};}
}

5. 测试

(1) 创建3层架构

分别在spring配置类和mvc配置类中添加包扫描:

@ComponentScan({"com.xjy.service"}) // spring包扫描
@ComponentScan("com.xjy.controller")//mvc包扫描

(2) 编写Controller层

@RestController
@RequestMapping("/user")
public class userController {@Autowiredprivate UserService userService;@GetMapping("/{id}")@ResponseBodypublic String getUserName(@PathVariable int id) throws IOException {System.out.println("接受到请求");String name = userService.getUserName(id);System.out.println("controller接受到返回结果"+name);return name;}
}

service层

接口:

package com.xjy.service;public interface UserService {String getUserName(int id);
}

实现类:

@Service
public class UserServiceImpl implements UserService {@Autowiredprivate SqlSession session;@Overridepublic String getUserName(int id) throws IOException {UserMapper mapper = session.getMapper(UserMapper.class);String name = mapper.getUserName(id);return name;}
}

mapper(dao)层

接口:

public interface UserMapper {String getUserName(int id);
}

sql映射文件:

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapperPUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""https://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.xjy.mapper.UserMapper"><select id="getUserName" resultType="java.lang.String">select name from user where id = #{id}</select>
</mapper>

tomcat部署启动

打包方式修改为war:

访问路劲修改为/:

启动tomcat服务,用postman进行访问:

成功接收: